import { useCallback, useReducer, createContext, useContext } from "react";
import * as React from "react";
import { Item, ItemsApi, LayerProps, Permission, PermissionAction } from "../../../types";
import { useAuth } from "../../Auth";

type ActionType =
  | { type: "ADD"; permission: Permission }
  | { type: "REMOVE"; id: string };

type UsePermissionManagerResult = ReturnType<typeof usePermissionsManager>;

const PermissionContext = createContext<UsePermissionManagerResult>({
  permissions: [],
  setPermissionApi: () => { },
  setPermissionData: () => { },
  setAdminRole: () => { },
  hasUserPermission: () => true
});

function usePermissionsManager(initialPermissions: Permission[]): {
  permissions: Permission[];
  // eslint-disable-next-line no-unused-vars
  setPermissionApi: (api: ItemsApi<any>) => void;
  // eslint-disable-next-line no-unused-vars
  setPermissionData: (data: Permission[]) => void;
  // eslint-disable-next-line no-unused-vars
  setAdminRole: (adminRole: string) => void;
  // eslint-disable-next-line no-unused-vars
  hasUserPermission: (collectionName: string, action: PermissionAction, item?: Item, layer?: LayerProps) => boolean;
} {
  const [permissions, dispatch] = useReducer((state: Permission[], action: ActionType) => {
    switch (action.type) {
      case "ADD":
        // eslint-disable-next-line no-case-declarations
        const exist = state.find((permission) =>
          permission.id === action.permission.id ? true : false
        );
        if (!exist) return [
          ...state,
          action.permission,
        ];
        else return state;

      case "REMOVE":
        return state.filter(({ id }) => id !== action.id);
      default:
        throw new Error();
    }
  }, initialPermissions);

  const [adminRole, setAdminRole] = React.useState<string | null>(null);
  const { user } = useAuth();


  const setPermissionApi = useCallback(async (api: ItemsApi<Permission>) => {   
    const result = await api.getItems();
    if (result) {
      result.map(permission => {
        dispatch({ type: "ADD", permission })
      })
    }
  }, [])

  const setPermissionData = useCallback((data: Permission[]) => {
    data.map(permission => {
      dispatch({ type: "ADD", permission })
    })
  }, []);

  const hasUserPermission = useCallback(
    (
      collectionName: string, 
      action: PermissionAction, 
      item?: Item, 
      layer?: LayerProps
    ) => {
      const evaluateCondition = (condition: any) => {
        if (condition.user_created?._eq === "$CURRENT_USER") {
          return item?.user_created?.id === user?.id;
        }
        if (condition.public_edit?._eq === true) {
          return item?.public_edit === true;
        }
        return false;
      };
  
      const evaluatePermissions = (permissionConditions: any) => {
        if (!permissionConditions || !permissionConditions._and) {
          return true;
        }
  
        return permissionConditions._and.every((andCondition: any) => 
          andCondition._or 
            ? andCondition._or.some((orCondition: any) => evaluateCondition(orCondition))
            : evaluateCondition(andCondition)
        );
      };
  
      // Bedingung für leere Berechtigungen nur, wenn NICHT item und create
      if (permissions.length === 0 && !(collectionName === "item" && action === "create")) return true;
      else if (user && user.role.id === adminRole) return true;
      else {
        return permissions.some(p =>
          p.action === action &&
          p.collection === collectionName &&
          (
            // Neue Bedingung für "item" und "create"
            (collectionName === "item" && action === "create" && layer?.public_edit_items === true) ||
            (
              (p.policy.name === user?.role.name &&
              (
                !item || evaluatePermissions(p.permissions)
              )) ||
              (p.policy == null &&
              (
                (layer?.public_edit_items || item?.layer?.public_edit_items) &&
                (!item || evaluatePermissions(p.permissions))
              ))
            )
          )
        );
      }
    },
    [permissions, user, adminRole]
  );
  
  



  return { permissions, setPermissionApi, setPermissionData, setAdminRole, hasUserPermission };
}

export const PermissionsProvider: React.FunctionComponent<{
  initialPermissions: Permission[], children?: React.ReactNode
}> = ({ initialPermissions, children }) => (
  <PermissionContext.Provider value={usePermissionsManager(initialPermissions)}>
    {children}
  </PermissionContext.Provider>
);

export const usePermissions = (): Permission[] => {
  const { permissions } = useContext(PermissionContext);
  return permissions;
};


export const useSetPermissionApi = (): UsePermissionManagerResult["setPermissionApi"] => {
  const { setPermissionApi } = useContext(PermissionContext);
  return setPermissionApi;
}

export const useSetPermissionData = (): UsePermissionManagerResult["setPermissionData"] => {
  const { setPermissionData } = useContext(PermissionContext);
  return setPermissionData;
}

export const useHasUserPermission = (): UsePermissionManagerResult["hasUserPermission"] => {
  const { hasUserPermission } = useContext(PermissionContext);
  return hasUserPermission;
}

export const useSetAdminRole = (): UsePermissionManagerResult["setAdminRole"] => {
  const { setAdminRole } = useContext(PermissionContext);
  return setAdminRole;
}